The invention relates to an arrangement and a method for determining the penetration depth when putting in place supporting elements into a water bed.
When placing piles or beams into a water bed, information on their loading capacity is often required. Generally for this, markings at fixed distances are placed on the beam elements to be put in place and the number of pile drives which must be made by a pile device are counted in order to achieve a certain penetration depth of the beam element. The number of pile drives gives an indication of the ground conditions and loading capacity, when taking account of the energy consumed. The known method is suitable for the putting in place of beam elements through water or on land, as well as foundation work in which the beam element and the pile device are located underwater.
In the case of underwater pile-driving, which may take place in depths of more than 1000 m, with a known arrangement for determining the penetration depth, an underwater camera is employed which permits an optical control of the markings on the supporting elements. The known arrangement on the one hand has the disadvantage that underwater cameras are prone to failure and with a breakdown, lead to the costly halting of the pile-driving operation. A further disadvantage lies in the fact that for monitoring the putting in place of the beam elements, a person is required to observe a monitor, and to manually protocol the progress of penetration.